I found three possibly useful WAV files (which I converted to OGG). One I think should be the Sunburst's firing sound.
In the demo, Warzone 2100 had explosion sounds of three intensities: small, medium, and large. The Warzone we now use is missing the Medium Explosion. Maybe this could be implemented sometime, maybe for the Sunburst, Medium Cannon, Tank Killer, Mortars, Rail Gun, and maybe others.
I also found a rocket firing sound, which is fitting for some rockets, like the Sunburst, Mini-pod, MRL (or whatever it's called now), Ripple Rockets, Seraph missiles, maybe even Scourge.
And lastly, I found an alternate Howitzer flight sound (in other words, when the shells are whizzing through the air).
IMPORTANT: I'm worse than a noob when it comes to licenses and everything. If something's wrong, please let me know.

